Improvement in the construction of spring-compasses



T. HA'GERTY,

`Improverr'lent inthe Construc-tiqn of Spring-Compasses.-

UNITED STATES PATENT OFFICE.

THOMAS HAGER-TY, or RICHMOND, viEeINiA.

IMPROVEMENT IN TH CCNSTRUCTION OF SPRINGCMPASSES.`

Specification forming part of Letters Patent No. 130,038, dated July 30, 1872.

To all whom it may concern:

` Be it known that I, THOMAS HAGERTY, of Richmond, Henrico county, State of Virginia, have invented a new and useful Improvement in vSpring-Compasses 5 and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing forming part of this specification, in which- Figure 1is a plan of the blank; and Fig. 2, a perspective view of the finished instrument. Similar letters of reference in the accompanying drawing denote the same parts.

The object of this invention is to improve the construction of spring-compasses so as to render them cheaper, lighter, and handsomer in shape and finish than heretofore; and to this end the invention consists in an improved article of manufacture-viz., spring-compasses struck up from fine -sheet metalas I willnow proceed to describe.

From a sheet or plate of` suitable metal, I cut out the blank A, shown in Fig. 1, such blank having a central portion, a, which afterwards becomes the spring, and the ends a1 a2,

which afterwards become the legs of the linished instrument. The centralpart ais formed,

preferably, with straight parallel edges. The

parta,1 tapers to a point, and is provided witha single aperture, m, arranged in line with the longer axis of the blank. The part a? likewise tapers to a point, and is provided with two small apertures, u fn, arranged at equal distances on each side of said axis, in a line crossing it at right angles, the said line and the aperture m being equidistant from the cen ter of the blank. The notches o o may be cut out, though this is not essential. One stroke of a suitable die will suffice to form the blank, as represented in Fig. l.

Having thus prepared the blank, I next, by

means of a pair of dies or a bending instru ment, turn the edges of the vmetal over from the points o o to the extremities, as shown in Fig. 2. The screw s will then be inserted through the hole m, and held by a rivet passing through `the holes n n. The instrument,

having been tempered either in the plate or cutting out the blank A, with its holes and its pointed extremities, as shown in Fig. Y

l, bending it to the shape represented in Fig. 2, and applying the screw s, substantially as and for thepurposes specified.

THOMAS Witnesses: N. K. ELLsWoRTn,

M. CHURCH.

The same construction may HAGEETY. 

